1
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Lin L, Zhao Y, Zheng Q, Zhang J, Li H, Wu W. Epigenetic targeting of autophagy for cancer: DNA and RNA methylation. Front Oncol 2023; 13:1290330. [PMID: 38148841 PMCID: PMC10749975 DOI: 10.3389/fonc.2023.1290330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 11/28/2023] [Indexed: 12/28/2023] Open
Abstract
Autophagy, a crucial cellular mechanism responsible for degradation and recycling of intracellular components, is modulated by an intricate network of molecular signals. Its paradoxical involvement in oncogenesis, acting as both a tumor suppressor and promoter, has been underscored in recent studies. Central to this regulatory network are the epigenetic modifications of DNA and RNA methylation, notably the presence of N6-methyldeoxyadenosine (6mA) in genomic DNA and N6-methyladenosine (m6A) in eukaryotic mRNA. The 6mA modification in genomic DNA adds an extra dimension of epigenetic regulation, potentially impacting the transcriptional dynamics of genes linked to autophagy and, especially, cancer. Conversely, m6A modification, governed by methyltransferases and demethylases, influences mRNA stability, processing, and translation, affecting genes central to autophagic pathways. As we delve deeper into the complexities of autophagy regulation, the importance of these methylation modifications grows more evident. The interplay of 6mA, m6A, and autophagy points to a layered regulatory mechanism, illuminating cellular reactions to a range of conditions. This review delves into the nexus between DNA 6mA and RNA m6A methylation and their influence on autophagy in cancer contexts. By closely examining these epigenetic markers, we underscore their promise as therapeutic avenues, suggesting novel approaches for cancer intervention through autophagy modulation.
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Affiliation(s)
- Luobin Lin
- Guangdong Province Key Laboratory of Biotechnology Drug Candidates, School of Life Sciences and Biopharmaceuticals, Guangdong Pharmaceutical University, Guangzhou, Guangdong, China
| | - Yuntao Zhao
- Guangdong Province Key Laboratory of Biotechnology Drug Candidates, School of Life Sciences and Biopharmaceuticals, Guangdong Pharmaceutical University, Guangzhou, Guangdong, China
| | - Qinzhou Zheng
- Guangdong Province Key Laboratory of Biotechnology Drug Candidates, School of Life Sciences and Biopharmaceuticals, Guangdong Pharmaceutical University, Guangzhou, Guangdong, China
| | - Jiayang Zhang
- Guangdong Province Key Laboratory of Biotechnology Drug Candidates, School of Life Sciences and Biopharmaceuticals, Guangdong Pharmaceutical University, Guangzhou, Guangdong, China
| | - Huaqin Li
- School of Health Sciences, Guangzhou Xinhua University, Guangzhou, Guangdong, China
| | - Wenmei Wu
- Guangdong Province Key Laboratory of Biotechnology Drug Candidates, School of Life Sciences and Biopharmaceuticals, Guangdong Pharmaceutical University, Guangzhou, Guangdong, China
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Shaposhnikov LA, Savin SS, Tishkov VI, Pometun AA. Ribonucleoside Hydrolases-Structure, Functions, Physiological Role and Practical Uses. Biomolecules 2023; 13:1375. [PMID: 37759775 PMCID: PMC10526354 DOI: 10.3390/biom13091375] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 09/01/2023] [Accepted: 09/03/2023] [Indexed: 09/29/2023] Open
Abstract
Ribonucleoside hydrolases are enzymes that catalyze the cleavage of ribonucleosides to nitrogenous bases and ribose. These enzymes are found in many organisms: bacteria, archaea, protozoa, metazoans, yeasts, fungi and plants. Despite the simple reaction catalyzed by these enzymes, their physiological role in most organisms remains unclear. In this review, we compare the structure, kinetic parameters, physiological role, and potential applications of different types of ribonucleoside hydrolases discovered and isolated from different organisms.
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Affiliation(s)
- Leonid A. Shaposhnikov
- Bach Institute of Biochemistry, Federal Research Centre “Fundamentals of Biotechnology” of the Russian Academy of Sciences, Moscow 119071, Russia; (S.S.S.); (V.I.T.)
- Department of Chemical Enzymology, Chemistry Faculty, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Svyatoslav S. Savin
- Bach Institute of Biochemistry, Federal Research Centre “Fundamentals of Biotechnology” of the Russian Academy of Sciences, Moscow 119071, Russia; (S.S.S.); (V.I.T.)
- Department of Chemical Enzymology, Chemistry Faculty, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Vladimir I. Tishkov
- Bach Institute of Biochemistry, Federal Research Centre “Fundamentals of Biotechnology” of the Russian Academy of Sciences, Moscow 119071, Russia; (S.S.S.); (V.I.T.)
- Department of Chemical Enzymology, Chemistry Faculty, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Anastasia A. Pometun
- Bach Institute of Biochemistry, Federal Research Centre “Fundamentals of Biotechnology” of the Russian Academy of Sciences, Moscow 119071, Russia; (S.S.S.); (V.I.T.)
- Department of Chemical Enzymology, Chemistry Faculty, Lomonosov Moscow State University, Moscow 119991, Russia
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Lin C, Jaén Batista DDG, Mazzeti AL, Donola Girão R, de Oliveira GM, Karalic I, Hulpia F, Soeiro MDNC, Maes L, Caljon G, Van Calenbergh S. N 6-modification of 7-Deazapurine nucleoside analogues as Anti-Trypanosoma cruzi and anti-Leishmania agents: Structure-activity relationship exploration and In vivo evaluation. Eur J Med Chem 2022; 231:114165. [PMID: 35144125 DOI: 10.1016/j.ejmech.2022.114165] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 01/26/2022] [Accepted: 01/26/2022] [Indexed: 11/18/2022]
Abstract
Chagas disease and leishmaniasis are two poverty-related neglected tropical diseases that cause high mortality and morbidity. Current treatments suffer from severe limitations and novel, safer and more effective drugs are urgently needed. Both Trypanosoma cruzi and Leishmania are auxotrophic for purines and absolutely depend on uptake and assimilation of host purines. This led us to successfully explore purine nucleoside analogues as chemotherapeutic agents against these and other kinetoplastid infections. This study extensively explored the modification of the 6-amino group of tubercidin, a natural product with trypanocidal activity but unacceptable toxicity for clinical use. We found that mono-substitution of the amine with short alkyls elicits potent and selective antitrypanosomal and antileishmanial activity. The methyl analogue 15 displayed the best in vitro activity against both T. cruzi and L. infantum and high selectivity versus host cells. Oral administration for five consecutive days in an acute Chagas disease mouse model resulted in significantly reduced peak parasitemia levels (75, 89 and 96% with 12.5, 25 and 50 mg/kg/day, respectively). as well as increased animal survival rates with the lower doses (83 and 67% for 12.5 and 25 mg/kg/day, respectively).
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Affiliation(s)
- Cai Lin
- Laboratory for Medicinal Chemistry (Campus Heymans), Ghent University, Ottergemsesteenweg 460, B-9000, Gent, Belgium
| | - Denise da Gama Jaén Batista
- Laboratório de Biologia Celular, Instituto Oswaldo Cruz (FIOCRUZ), Fundação Oswaldo Cruz, Rio de Janeiro, Avenida Brasil 4365, Manguinhos, 21040-360, Rio de Janeiro, Brazil
| | - Ana Lia Mazzeti
- Laboratório de Biologia Celular, Instituto Oswaldo Cruz (FIOCRUZ), Fundação Oswaldo Cruz, Rio de Janeiro, Avenida Brasil 4365, Manguinhos, 21040-360, Rio de Janeiro, Brazil
| | - Roberson Donola Girão
- Laboratório de Biologia Celular, Instituto Oswaldo Cruz (FIOCRUZ), Fundação Oswaldo Cruz, Rio de Janeiro, Avenida Brasil 4365, Manguinhos, 21040-360, Rio de Janeiro, Brazil
| | - Gabriel Melo de Oliveira
- Laboratório de Biologia Celular, Instituto Oswaldo Cruz (FIOCRUZ), Fundação Oswaldo Cruz, Rio de Janeiro, Avenida Brasil 4365, Manguinhos, 21040-360, Rio de Janeiro, Brazil
| | - Izet Karalic
- Laboratory for Medicinal Chemistry (Campus Heymans), Ghent University, Ottergemsesteenweg 460, B-9000, Gent, Belgium
| | - Fabian Hulpia
- Janssen Pharmaceutica NV, Turnhoutseweg 30, 2340, Beerse, Belgium
| | - Maria de Nazaré C Soeiro
- Laboratório de Biologia Celular, Instituto Oswaldo Cruz (FIOCRUZ), Fundação Oswaldo Cruz, Rio de Janeiro, Avenida Brasil 4365, Manguinhos, 21040-360, Rio de Janeiro, Brazil
| | - Louis Maes
- Laboratory of Microbiology, Parasitology and Hygiene (LMPH), Infla-Med Centre of Excellence, University of Antwerp, Universiteitsplein 1, B-2610, Wilrijk, Belgium
| | - Guy Caljon
- Laboratory of Microbiology, Parasitology and Hygiene (LMPH), Infla-Med Centre of Excellence, University of Antwerp, Universiteitsplein 1, B-2610, Wilrijk, Belgium
| | - Serge Van Calenbergh
- Laboratory for Medicinal Chemistry (Campus Heymans), Ghent University, Ottergemsesteenweg 460, B-9000, Gent, Belgium.
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Malki Y, Martinez J, Masurier N. 1,3-Diazepine: A privileged scaffold in medicinal chemistry. Med Res Rev 2021; 41:2247-2315. [PMID: 33645848 DOI: 10.1002/med.21795] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 01/20/2021] [Accepted: 02/17/2021] [Indexed: 12/19/2022]
Abstract
Privileged structures have been widely used as effective templates for drug discovery. While benzo-1,4-diazepine constitutes the first historical example of such a structure, the 1,3 analogue is just as rich in terms of applications in medicinal chemistry. The 1,3-diazepine moiety is present in numerous biological active compounds including natural products, and is used to design compounds displaying a large range of biological activities. It is present in the clinically used anticancer compound pentostatin, in several recent FDA approved β-lactamase inhibitors (e.g., avibactam) and also in coformycin, a natural product known as a ring-expanded purine analogue displaying antiviral and anticancer activities. Several other 1,3-diazepine containing compounds have entered into clinical trials. This heterocyclic structure has been and is still widely used in medicinal chemistry to design enzyme inhibitors, GPCR ligands, and so forth. This review endeavours to highlight the main use of the 1,3-diazepine scaffold and its derivatives, and their applications in medicinal chemistry, drug design, and therapy. We will focus more particularly on the development of enzyme inhibitors incorporating this scaffold, with a strong emphasis on the molecular interactions involved in the inhibition mechanism.
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Affiliation(s)
- Yohan Malki
- IBMM, Université de Montpellier, CNRS, ENSCM, Montpellier, France
| | - Jean Martinez
- IBMM, Université de Montpellier, CNRS, ENSCM, Montpellier, France
| | - Nicolas Masurier
- IBMM, Université de Montpellier, CNRS, ENSCM, Montpellier, France
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Investigations into specificity of azepinomycin for inhibition of guanase: discrimination between the natural heterocyclic inhibitor and its synthetic nucleoside analogues. Bioorg Med Chem Lett 2012; 22:7214-8. [PMID: 23084905 DOI: 10.1016/j.bmcl.2012.09.053] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Revised: 09/11/2012] [Accepted: 09/17/2012] [Indexed: 01/05/2023]
Abstract
In our long and broad program to explore structure-activity relationships of the natural product azepinomycin and its analogues for inhibition of guanase, an important enzyme of purine salvage pathway of nucleic acid metabolism, it became necessary to investigate if the nucleoside analogues of the heterocycle azepinomycin, which are likely to be formed in vivo, would be more or less potent than the parent heterocycle. To this end, we have resynthesized both azepinomycin (1) and its two diastereomeric nucleoside analogues (2 and 3), employing a modified, more efficient procedure, and have biochemically screened all three compounds against a mammalian guanase. Our results indicate that the natural product is at least 200 times more potent toward inhibition of guanase as compared with its nucleoside analogues, with the observed K(i) of azepinomycin (1) against the rabbit liver guanase=2.5 (±0.6)×10(-6) M, while K(i) of Compound 2=1.19 (±0.02)×10(-4) M and that of Compound 3=1.29 (±0.03)×10(-4) M. It is also to be noted that while IC(50) value of azepinomycin against guanase in cell culture has long been reported, no inhibition studies nor K(i) against a pure mammalian enzyme have ever been documented. In addition, we have, for the first time, determined the absolute stereochemistry of the 6-OH group of 2 and 3 using conformational analysis coupled with 2-D (1)H NMR NOESY.
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Serafim TD, Figueiredo AB, Costa PAC, Marques-da-Silva EA, Gonçalves R, de Moura SAL, Gontijo NF, da Silva SM, Michalick MSM, Meyer-Fernandes JR, de Carvalho RP, Uliana SRB, Fietto JLR, Afonso LCC. Leishmania metacyclogenesis is promoted in the absence of purines. PLoS Negl Trop Dis 2012; 6:e1833. [PMID: 23050028 PMCID: PMC3458635 DOI: 10.1371/journal.pntd.0001833] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Accepted: 08/13/2012] [Indexed: 02/04/2023] Open
Abstract
Leishmania parasites, the causative agent of leishmaniasis, are transmitted through the bite of an infected sand fly. Leishmania parasites present two basic forms known as promastigote and amastigote which, respectively, parasitizes the vector and the mammalian hosts. Infection of the vertebrate host is dependent on the development, in the vector, of metacyclic promastigotes, however, little is known about the factors that trigger metacyclogenesis in Leishmania parasites. It has been generally stated that "stressful conditions" will lead to development of metacyclic forms, and with the exception of a few studies no detailed analysis of the molecular nature of the stress factor has been performed. Here we show that presence/absence of nucleosides, especially adenosine, controls metacyclogenesis both in vitro and in vivo. We found that addition of an adenosine-receptor antagonist to in vitro cultures of Leishmania amazonensis significantly increases metacyclogenesis, an effect that can be reversed by the presence of specific purine nucleosides or nucleobases. Furthermore, our results show that proliferation and metacyclogenesis are independently regulated and that addition of adenosine to culture medium is sufficient to recover proliferative characteristics for purified metacyclic promastigotes. More importantly, we show that metacyclogenesis was inhibited in sand flies infected with Leishmania infantum chagasi that were fed a mixture of sucrose and adenosine. Our results fill a gap in the life cycle of Leishmania parasites by demonstrating how metacyclogenesis, a key point in the propagation of the parasite to the mammalian host, can be controlled by the presence of specific purines.
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Affiliation(s)
- Tiago Donatelli Serafim
- Laboratório de Imunoparasitologia, Departamento de Ciências Biológicas, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, Brazil
| | - Amanda Braga Figueiredo
- Laboratório de Imunoparasitologia, Departamento de Ciências Biológicas, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, Brazil
| | - Pedro Augusto Carvalho Costa
- Laboratório de Imunoparasitologia, Departamento de Ciências Biológicas, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, Brazil
| | - Eduardo Almeida Marques-da-Silva
- Laboratório de Imunoparasitologia, Departamento de Ciências Biológicas, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, Brazil
| | - Ricardo Gonçalves
- Laboratório de Imunoparasitologia, Departamento de Ciências Biológicas, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, Brazil
| | - Sandra Aparecida Lima de Moura
- Laboratório de Imunopatologia, Departamento de Ciências Biológicas, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, Brazil
| | - Nelder Figueiredo Gontijo
- Laboratório de Fisiologia de Insetos Hematófagos, Departamento de Parasitologia/ICB, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Sydnei Magno da Silva
- Laboratório de Sorologia, Departamento de Parasitologia/ICB, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | | | - José Roberto Meyer-Fernandes
- Laboratório de Bioquímica Celular, Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Roberto Paes de Carvalho
- Laboratório de Neurobiologia Celular, Departamento de Neurobiologia/Programa de Neurociências, Universidade Federal Fluminense, Niterói, Brazil
| | - Silvia Reni Bortolin Uliana
- Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - Juliana Lopes Rangel Fietto
- Laboratório de Infectologia Molecular Animal, Departamento de Bioquímica e Biologia Molecular/Bioagro, Universidade Federal de Viçosa, Viçosa, Brazil
| | - Luís Carlos Crocco Afonso
- Laboratório de Imunoparasitologia, Departamento de Ciências Biológicas, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, Brazil
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Fernández JR, Sweet ES, Welsh WJ, Firestein BL. Identification of small molecule compounds with higher binding affinity to guanine deaminase (cypin) than guanine. Bioorg Med Chem 2010; 18:6748-55. [PMID: 20716488 DOI: 10.1016/j.bmc.2010.07.054] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2010] [Revised: 07/15/2010] [Accepted: 07/22/2010] [Indexed: 10/19/2022]
Abstract
Guanine deaminase (GDA; cypin) is an important metalloenzyme that processes the first step in purine catabolism, converting guanine to xanthine by hydrolytic deamination. In higher eukaryotes, GDA also plays an important role in the development of neuronal morphology by regulating dendritic arborization. In addition to its role in the maturing brain, GDA is thought to be involved in proper liver function since increased levels of GDA activity have been correlated with liver disease and transplant rejection. Although mammalian GDA is an attractive and potential drug target for treatment of both liver diseases and cognitive disorders, prospective novel inhibitors and/or activators of this enzyme have not been actively pursued. In this study, we employed the combination of protein structure analysis and experimental kinetic studies to seek novel potential ligands for human guanine deaminase. Using virtual screening and biochemical analysis, we identified common small molecule compounds that demonstrate a higher binding affinity to GDA than does guanine. In vitro analysis demonstrates that these compounds inhibit guanine deamination, and more surprisingly, affect GDA (cypin)-mediated microtubule assembly. The results in this study provide evidence that an in silico drug discovery strategy coupled with in vitro validation assays can be successfully implemented to discover compounds that may possess therapeutic value for the treatment of diseases and disorders where GDA activity is abnormal.
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Affiliation(s)
- José R Fernández
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, 604 Allison Road, Piscataway, NJ 08854-8082, USA
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8
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Wang L, Hosmane RS. A unique ring-expanded acyclic nucleoside analogue that inhibits both adenosine deaminase (ADA) and guanine deaminase (GDA; guanase): synthesis and enzyme inhibition studies of 4,6-diamino-8H-1-hydroxyethoxymethyl-8-iminoimidazo[4,5-e][1,3]diazepine. Bioorg Med Chem Lett 2001; 11:2893-6. [PMID: 11677121 DOI: 10.1016/s0960-894x(01)00591-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The synthesis and enzyme inhibition studies of a novel ring-expanded acyclic nucleoside analogue are reported. Compound has been found to be a competitive inhibitor of both adenosine deaminase (ADA) and guanine deaminase (GDA; guanase) with K(i)'s equal to 1.52+/-0.34 x 10(-4) M and 2.97+/-0.25 x 10(-5) M, respectively. Inhibition of two enzymes of purine metabolism may bear beneficial implications in antiviral therapy.
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Affiliation(s)
- L Wang
- Laboratory for Drug Design and Synthesis, Department of Chemistry & Biochemistry, University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA
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9
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Hassan HF, Coombs GH. Leishmania mexicana: purine-metabolizing enzymes of amastigotes and promastigotes. Exp Parasitol 1985; 59:139-50. [PMID: 2982637 DOI: 10.1016/0014-4894(85)90066-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Cultured promastigote and isolated amastigote forms of Leishmania mexicana mexicana have been surveyed for the presence of enzymes involved in purine metabolism. Quantitative but not qualitative differences between the enzymes of two forms were discovered. There were found to be significant differences between the enzyme content of L. m. mexicana and that reported for L. donovani. Extracts of both parasite forms of L. m. mexicana were found to have higher levels of adenine deaminase (EC 3.5.4.2) and guanine deaminase (EC 3.5.4.3) than adenosine deaminase (EC 3.5.4.4). There appeared to be two distinct nucleosidases (EC 3.2.2.1), one active on nucleosides, the other on deoxynucleosides. Phosphorylase (EC 2.4.2.1) could be detected only in the catabolic direction. Nucleotidases were present, but were more active on 3' (EC 3.1.3.6)- than 5' (EC 3.1.3.5)-nucleotides. Phosphoribosyltransferase (EC 2.4.2.7,.8 and .22) and nucleoside kinase (EC 2.7.1.20) activities were detected in both forms. Nucleotide-interconverting enzymes were found to be present, with IMP dehydrogenase (EC 1.2.1.14) being the most active. Cell fractionation experiments revealed that, in the promastigote, enzyme separation within the parasite may play an important part in regulating cellular purine metabolism.
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Hassan HF, Coombs GH. Purine phosphoribosyltransferases of Leishmania mexicana mexicana and other flagellate protozoa. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. B, COMPARATIVE BIOCHEMISTRY 1985; 82:773-9. [PMID: 3937660 DOI: 10.1016/0305-0491(85)90524-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Amastigotes and cultured promastigotes of Leishmania mexicana mexicana and L. m. amazonensis, cultured promastigotes of L. donovani and L. tarentolae, and the culture forms of Crithidia fasciculata, Herpetomonas muscarum muscarum and H. m. ingenoplastis all possessed four phosphoribosyltransferase (PRTase) activities: adenine PRTase, hypoxanthine PRTase, guanine PRTase and xanthine PRTase. The enzymes of L. m. mexicana required divalent cations for activity; Mn2+ or Co2+ produced maximal activity in most cases. Hypoxanthine PRTase, guanine PRTase and xanthine PRTase from all organisms were sedimentable in part, suggesting that they may occur within glycosomes. The enzymes of L. m. mexicana cultured promastigotes were inhibited by a range of purine analogues.
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Abstract
The pathways leading to purine and pyrimidine nucleotide production in members of the family Trypanosomatidae are discussed with special emphasis on data relating to pathogenic species published from 1974 to 1983 inclusive. Trypanosomes and leishmania in general lack a de novo purine biosynthetic pathway, but have a multiplicity of possible routes for purine salvage. In contrast, pyrimidine nucleotides can be produced by either de novo or salvage pathways. The properties of these pathways in trypanosomatids are compared and contrasted with those of their hosts.
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12
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Partial purification and characterization of guanine aminohydrolase fromtrypanosoma cruzi. Curr Microbiol 1984. [DOI: 10.1007/bf01567163] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Kidder GW. Characteristics of cytidine aminohydrolase activity in Trypanosoma cruzi and Crithidia fasciculata. THE JOURNAL OF PROTOZOOLOGY 1984; 31:298-300. [PMID: 6381719 DOI: 10.1111/j.1550-7408.1984.tb02965.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Cytidine deaminase (cytidine aminohydrolase, 3.5.4.5) is present in Crithidia fasciculata (a mosquito parasite) and in Trypanosoma cruzi (a human pathogen). The enzyme from C. fasciculata deaminated both cytidine and deoxycytidine, the affinity for the former being much lower than the latter. Affinities for both substrates are equal for the T. cruzi enzyme. The production of the enzyme in C. fasciculata was significantly stimulated by the addition of a number of pyrimidine nucleosides (cytidine, uridine, 5-bromouridine, thymidine, orotidine) to the culture media. Only cytidine stimulated enzyme production in T. cruzi. The enzyme from both organisms was unstable in air, even in the frozen state. Stabilization was achieved under anaerobic conditions.
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14
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Davies MJ, Ross AM, Gutteridge WE. The enzymes of purine salvage in Trypanosoma cruzi, Trypanosoma brucei and Leishmania mexicana. Parasitology 1983; 87 (Pt 2):211-7. [PMID: 6316234 DOI: 10.1017/s0031182000052574] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
We have previously shown the presence of various purine salvage enzymes in Trypanosoma cruzi, including phosphoribosyltransferase, aminohydrolase, kinase, phosphorylase and hydrolase activities. We now report that a similar situation occurs in Leishmania mexicana amazonensis and Trypanosoma brucei brucei. In all three organisms we found higher levels of activity for the phosphoribosyltransferase enzymes than for the nucleoside kinases, suggesting a preference for the salvage of purine bases rather than nucleosides. Similarly, absence of inosine phosphorylase activity suggests that only one route for the salvage of hypoxanthine is available to the three organisms. The most striking difference was that whereas T. cruzi and T. brucei possessed adenosine aminohydrolase activity, this was not detected in L. mexicana; instead adenine aminohydrolase activity was found. The overall similarity, as judged by the distribution of enzyme activities, of purine salvage in these three members of the kinetoplastida suggest a broad spectrum of activity for any inhibitor acting in this area; the plethora of alternative salvage pathways, however, suggests that in no case would such inhibition be cidal.
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15
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Kidder GW, Nolan LL. Xanthine phosphoribosyltransferase in Leishmania: divalent cation activation. THE JOURNAL OF PROTOZOOLOGY 1982; 29:405-9. [PMID: 7131352 DOI: 10.1111/j.1550-7408.1982.tb05422.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Xanthine phosphoribosyltransferase (XPRTase; EC 2.4.4.22) was found in the promastigotes of four species of Leishmania (L. mexicana, L. donovani, L. braziliensis and L. tarentolae). In no case was there any transribosylation from 5-phosphoribosyl-1-pyrophosphate (PRibPP), forming XMP, in dialyzed preparations, unless activated by a divalent cation. Magnesium and zinc were very low in activation efficiency in all cases, while manganese was optimally efficient. Cobalt was essentially equal to manganese for activation of the enzyme from L. mexicana and L. braziliensis but much less efficient for the enzyme from L. donovani and L. tarentolae. Gel filtration profiles of cell extracts of L. mexicana on Sephadex G-200 indicated that the enzymes catalyzing the transribosylation from PRibPP to guanine, hypoxanthine, and xanthine were inseparable. All were eluted near the void volume. The enzyme for adenine transribosylation was clearly separate. When cell extracts of L. mexicana were applied to Sephadex G-100 columns, the activity toward XMP formation from xanthine eluted with the void volume, together with a portion of that for the formation of GMP and IMP from guanine and hypoxanthine. A second peak of HGPRTase (EC 2.4.2.8) eluted somewhat later and was devoid of XPRTase activity. XPRTase from promastigotes of L. mexicana is heat labile, has rather a broad pH optima, and is stable to freezing when protected by nonspecific cell protein (40,000 g supernate as opposed to 100,000 g supernates).
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Spector T, Berens RL, Marr JJ. Adenylosuccinate synthetase and adenylosuccinate lyase from Trypanosoma cruzi, Specificity studies with potential chemotherapeutic agents. Biochem Pharmacol 1982; 31:225-9. [PMID: 7037007 DOI: 10.1016/0006-2952(82)90215-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Adenylosuccinate (succino-AMP) synthetase and succino-AMP lyase isolated from epimastigotes of Trypanosoma cruzi by chromatography on phosphocellulose. The synthetase was capable of catalyzing the condensation of aspartic acid with IMP and several IMP analogs. The reaction with allopurinol ribonucleotide is of potential chemotherapeutic interest. This analog was slowly converted to its corresponding succino-AMP analog with a Km' of 140 micrometers (cf. IMP at 10 micrometers) and a Vmax' of 0.3 per cent the rate with IMP. The comparable reaction with this analog does not occur with succino-AMP synthetase from a representative mammalian source [T. Spector and R. L. Miller, Biochim. biophys. Acta 455, 509 (1976)]. The protozoal succino-AMP lyase had a broad substrate which was characteristic of this enzyme from many sources. It catalyzed the rapid and efficient cleavage of all the succino-AMP analogs that were produced by succino-AMP synthetase. Thus, these two enzymes appear to be responsible for the selective amination of allopurinol ribonucleotide in T. cruzi. The metabolically produced AMP analog may be the agent or a precursor of the agent that accounts for the anti-growth activity of allopurinol in these organisms. Similar selective amination was observed previously with these enzymes from Leishmania donovani [T. Spector, T. E. Jones and G. B. Elion, J. biol. Chem. 254, 8422 (1979)]. Thiopurinol ribonucleotide was not a substrate of succino-AMP synthetase from T. cruzi, but it was an inhibitor with a K1 = 33 micrometers. Therefore, the weakness of thiopurinol's anti-growth activity with T. cruzi is not due to its inability to inhibit this enzyme.
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Kidder GW, Nolan LL. The in vivo and in vitro action of 4-amino-5-imidazolecarboxamide in trypanosomatid flagellates. Mol Biochem Parasitol 1981; 3:265-9. [PMID: 7029273 DOI: 10.1016/0166-6851(81)90001-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
4-Amino-5-imidazolecarboxamide, but not its riboside or ribotide, is inhibitory to the growth of promastigotes of Leishmania donovani, L. braziliensis, L. tarentolae, and L. mexicana, eventually causing cell lysis. Conversely, it is not inhibitory to the growth of epimastigotes of Trypanosoma cruzi. This substituted imidazole proved to be an excellent inhibitor of guanine deaminase from all of the trypanosomatids used in this study, with Ki values in the microM range.
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Wang CC. Chapter 24. Recent Advances in Parasite Biochemistry. ANNUAL REPORTS IN MEDICINAL CHEMISTRY 1981. [DOI: 10.1016/s0065-7743(08)61291-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/13/2023]
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